The device doesn't have internal storage and boots from the SD-card. The second and third stage loader (SPL and U-Boot) are loaded from the start of the MMC (not on a file system). The default configuration is to create two partitions the first is a FAT formatted one where u-boot will load files from and the second one probably a ext2 partition. But given the bootloaders are not on the FAT you need to reserve some space at the start (I leave 2048 512 byte blokcs at the start as this is the default fdisk offers).

Flyswatter 2 / OpenOCD

Boot Layout

The device doesn't have internal storage and boots from the SD-card. The second and third stage loader (SPL and U-Boot) are loaded from the start of the MMC (not on a file system). The default configuration is to create two partitions the first is a FAT formatted one where u-boot will load files from and the second one probably a ext2 partition. But given the bootloaders are not on the FAT you need to reserve some space at the start (I leave 2048 512 byte blokcs at the start as this is the default fdisk offers).